Page 298 - Handbook of Biomechatronics

290 Andres F. Ruiz-Olaya et al.

Hardiman (“Human Augmentation Research and Development Investiga-
tion”). The prototype remained incomplete at the time of its termination
(Kazerooni et al., 1968). General Electric Co. developed the concept of
human-amplifiers through the Hardiman project from 1966 to 1971. The
Hardiman concept was a robotic master/slave configuration in which two
overlapping exoskeletons were implemented. The inner one was set to fol-
low human motion while the outer one implemented an hydraulically emp-
owered version of the motion performed by the inner exoskeleton
(Kazerooni, 1990).
Other research projects were conducted in Serbia in the 1970s (Hristic
and Vukobratovic, 1973), and at the Massachusetts Institute Technology
(MIT) in the 1980s (Seireg and Grundman, 1981). However, few studies
were carried on during the next 20 years because of fundamental technolog-
ical limitations, especially in control hardware. At the end of the 20th cen-
tury, with the rapid progress in computer science, as well as control and drive
technologies, the Defense Advanced Research Projects Agency (DARPA),
an agency of the Department of Defense of the USA, started new efforts in
the development of exoskeletons (Garcia et al., 2002). This renewed interest
in the United States led other groups and institutes in other countries
(including Japan, Russia, the United Kingdom, Germany, Korea, and
Singapore) to start their own projects (Li et al., 2014). Many results have
been published since the beginning of the 21st century, as well as several
reviews discussing the state-of-the-art and future perspectives (Dollar and
Hugh, 2008; Yang et al., 2008; Kazerooni, 2008).
Rehabilitation and functional compensation are very important potential
applications of exoskeletons and wearable robotics. Worldwide, an esti-
mated 185 million people use wheelchairs and other functional assistance
devices daily. Furthermore, almost 20% of the world’s population is now
aged over 65 years, and this proportion may exceed 35% until 2050.
The assistive rehabilitation exoskeletons have the potential for use in many
applications, and a very important use in the near future should be in the
rehabilitation of upper and lower limbs.

2.1 Upper Extremity Exoskeletons

The primary applications of upper-limb exoskeletons were originally
teleoperation and power amplification. An example is the ESA human
arm exoskeleton for Space Robotics Telepresence (Schiele and Van der
Helm, 2006), developed as a human-machine interface for master-slave